Heat exchanger cleaning device



Ap 7,1953 R. w. DRAKE HEAT EXCHANGER CLEANING DEVICE 2 SI-lEETS-SHEET 1 Filed Nov. 15, 1946 I J f 3% mp m r U E M K Y BY /7 J April 7, 9 R. w. DRAKE 2 2,634,164

HEAT EXQHANGER CLEANING DEVICE Filed Nov. 15, 1946 'z sHEETs-srmm 2 IIIIIIIIIIIIIIIII/III I 'l l/Z INVENTOR. 2 I h kaaikr MID/99m.

II By be set forth more fully hereinafter.

Patented Apr. 7, 1953 j UNITED, STATES PATENT OFFICE." I

2,634,164 HEAT EXCHANGER CLEANING DEVICE I Robert w. Drake, Tulsa, Okla.

Application November 15, 1946, Serial No. 710,040

1 This invention relates to cleaning of heat changers having tubes or tube bundles.

Heat exchangers of this general type may have a few tubes or as many as several hundred, and although such exchangers are used for a great many and variety of materials they all have the same general function.

Ordinarily the product to b cooled is allowed "to flow through the tubes and the cooling medium, usually water, is allowed to circulate around the outside of the tubes but within the casing,

commonly termed the shell.

, Usually units are connected in series, parallel.

or series-parallel relation in the requisite number' to eiiect. the desired heat transference. In certain installations where the product to be. cooled is unusually hot, scales and sludges accumulate around the outside of tubes up n the shell exposed portions thereof.

. The chief object of the present invention is to remove such accumulations through means capable of inclusion in old or new exchangers without necessitating the dismantling for cleaning of such and when desired associating therewith a, localizing chemical supply tube whereby selected sections of the spray tube are pressure supplied with liquid chemical'under pressure. The chemical spraying of. the exterior or the adjacent heat transfertubes effects dissolution and separation of such scale and sludge from the heat transfer tube exteriors so that the efiiciency thereof is reestablished. The Separated sludge and scale dey posits in the bottom of the exchanger casing from whence same may be readily'removed from the heatexchange unit.

Other objects and features of the invention will I V The fun nature or the "ention will be undertood from the accompanyi drawings and the following description and claims:

'In the drawings Fig. 1 is a longitudinal sectional view through one form of heat exchanger unit equipped with one form of the invention.

Fig. 2 is a diagrammatic layout of one arrangement of the conventional tube and the cleanin tube. V

Fig. 3 is an enlarged transverse sectional view of a cleaning tube shown in Figs. 1' and 2. Flgleis a longitudinal sectional view of a'mode iiled formoi the invention.

2 Claims. (01. 299-27) 2 Fig. 5 is a similar view of the same provided with a bridging tube. l

Fig. 6 is a similar view of a slightl modified form of the invention shown in Fig. 1.;

' Fig. '7 is a longitudinal sectional View of a cleaning tube and pressure chemical liquid supplying and localizing structure. Fig. 8 is a view similar to Fig.1 and of a modified form of cleaning tube structure and support at the remote end thereof.

Fig. 9 is a similar view of a U-shaped cleanin tube at the U-end thereof.

Fig. 10 is a centraisectional view of modified form of the invention wherein the exchanger is of non-floating head type and the cleaning tubes are of the tube sheet anchored type.

Fig. 11 is a similar view of a further form wherein the heat exchange tubes are of the return bend type and a part of the cleaning tubes are of return bend type shown in Fig. 9 and others are of the type shown in Fig. 1, although all may be of either type. h

Before proceeding to describe in detail several embodiments of the invention, herein set forth by way of example only, it appears highly desirable to describeone conventional type of heat exchanger to which same may be applied.

In Fig. 1, it indicates ashell'or casing, flanged at H and i2 and provided with an inlet 13 and outlet l4, or vice versa. A head l5, flanged at. [6, is secured to shell Ill at flange 12. Another head [1, flanged at I8, is secured to the shell at flange Interposed between the shell'and one head is a tube sheet Ill. The head I! is spacedfrom shell ill by said sheet. The head includes inlet 2| to chamber 22 formed by said baille' and an outlet 23: from chamber 24 formed by said bailie.

Flow obviously may be reversed.

Within the head I5 is a floating head structure 25' andtubes 26 and 21 are securedv at op- 1 posite ends to that head structure and the tube sheet le'in conventional manner so that. the circulation is from chamber 22 to head 25 and from same tov chamber 24 or. vice versa.

If hot liquid or vapor be thus circulated and cold water passed through the shell, etc.,' the' tube (26-21) confined prQduct will be cooled and tion of apparatus whereby the exchanger may. he

reconditioned without necessitating disassembly and manual removal of such sludge and scale.

The tubes 26-21 are arranged in bundles or as desired and are of the requisite number. Herein there is secured cleaning tubes 28 properly distributed and disposed so that chemical liquid discharged from orifices 29 suitably disposed upon the length of and around each tube 28, will impinge upon substantially all of the tubes 26-2! and upon substantially the entire length thereof exposed shell" Ill.

Preferably the supply to the tubes 26-21 is cut off and the supply to the shell is cut off and the unit in question drained. Then chemical liquid is supplied under pressure to the supply ends of cleaning tubes 28 until the scale and sludge collected upon tubes 26-41 separates therefrom and falls to the bottom of the shell.

It can then readily be removed by flushing or provided when desired or required. For the preferred (localized selective) operation the interior of tube 28 should be free of all obstructions.

In Fig. 4 the supply end of cleaning tube 28 is secured to tube sheet 19 and opens upon the chamber formed thereby. A threaded plug 3t normally closes this end of the tube. In longitudinal alignment with tube 28 said head has opening 3| normally closed and sealed by threadedplug 32.

When cleaning is to be effected plugs 32 and 30 may be removed and the chemical supply tube operatively connected to tube 28 at sheet id, being introduced thereto through opening 3| which, see Fig. 4, is larger than the tube sheet opening closure (plug 30).

' The foregoing describes a modification of the invention shown in Fig. 1 wherein cleaning tube 28 is extended through chamber 22"or 24 as at 28 and through opening 3i in the head I1. Ex-

tension 28 may comprise a nipple,. see Fig. 5. Cap 33 herein closes the head opening 3I and envelopescap 34 applied to the head exposed end of nipple 28F.

Removal of both caps permits the chemical liquid supply tube to be applied to tube 28-2B Whenever the tube 28 and its extension 28 is continuous or Whenever the dual cap arrangement is not desired, the tube 28 or nipple 28, as the case may be, respectively, extends through the opening 3| see Fig. 6, which is shouldered at 3I A packing gland structure 32 seals the the cleaning tube and normal closing of same aswell as rendering that closed end readily accessible for conduit connection for chemical liquid supply thereto.

The aforesaid pressure supply conduit may be 'a valve controlled pressure tube which when connected to tube 28 or extension 28 insures pressure discharge from all ports 29 therein.

However, when localized directional cleaning is desired thepressure supply tube structure includes additional parts and same isimore' fully at 51 for obvious reasons. cleaning arrangement.

4 illustrated in Fig. 7 to which reference will now be had.

Herein 35 indicates a valve controlled flexible hose discharging to one end of a tube 36 closed at the opposite end as at 37, which may be an exter nally flanged cap provided with shoulder or fixed collar portion 38.

Adjacent thereto and enveloping the tube 36 is the annular packing or ring 39. Spaced therefrom is a similar ring 40. Therebetween is a flanged or shouldered-sleeve il that includes longitudinal slots 42 therein. Collars or shoulders 43 and 44 at opposite ends confront said rings. A metal bearing washer or ring 45 is oppositelydisposed relative to collar 44 with ring til. therebetween.

A tightening ferrule or tube 46 envelopes tube 36 and is slidable thereon and rotatable thereon. The end 47 bears against Washer 45. Tube 36 is externally threaded as at 48. Tube 46 adjacent ring 45 has an internal collar 49 threaded as at 50. Tube 36 also includes ports 5|.

Since the diameters of tubes 36, 46, cap 31 (with flange 33) and collar portions 4344 are less than the inside diameter of tube 28, the entire structure aforesaid can be positioned as desired in said tube 28 and then tube 46 rotated relative to supply tube 36.

By virtue of. the thread connection therebetween pressure is exerted upon the packing rings 39 and 46 to expand radially same into sealing relation within said tube 28 and thus localize a portion thereof. Pressure fluid supplied to tube 36 than escapes by ports SI and slots 42 to the localized portion of tube 28 so that chemical spray is only discharged therefrom by ports 29 which then are in free communication with tube 36.

When spraying is elfected the tube or ferrule 46 is unthreaded and the structure repositioned as aforesaid or removed and applied to another cleaning tube 28 for the cleaning of other heat exchange tubes 262'I. 1

Reference will now be had to Figs. 1, 8 and 9. In Fig. 1 tubes 23, at the remote end as distinguished from the supply end, are suitably closed by capping as at 52. Whenever desired, see Fig. 8, the said remote ends may be supported'by the rear tube sheet 25 and plugged as at 55.

Whenever this type of support is not desired certain of the cleaning tubes may be mechanically connected, see Fig. 9. Herein the remote ends are united as at 56 by a curved tubular portionand, preferably approximately midway thereof, said tube is plugged or blocked as This is a U-shaped In Fig. 10 there is illustrated what might be designated the right hand portion of a heat exetc., to this head, the end I I2 of the casing being herein defined by a tube sheet I25**. I

Each of the several tubes I26 and I2! are sultably anchored or secured in and to the tube sheet .I25*- and communicate with the interior of the head II5 which, of course, is sealed off by the sheet from the interior of the casing H0.

In the present form of theiexchanger it: is preferred to secure each of the cleaning tubes I28 perforated or provided with nozzles as at I29 by securing the same in the tube sheet comparable to the method disclosed in Fig. 8 and then plugging the tube sheet anchored ends by the expansion plugs I55. If it is not desired to have these ends of the cleaning tubes anchored, they may terminate immediately adjacent the tube sheet and be closed by the cap structure comparable to the cap 52 shown in Fig. 1.

Reference will now be had to Fig. 11 wherein the casing 2|0 is provided with flange 212', to which is secured a head 215. Herein the tubes 226 and 221 are connected together by the curved portions 225 so that the tubes 226 and 22'! are in effect return bend tube stabilizing.

Racks or spacers may be provided, if desired, but same are not shown herein for they form no part of the present invention.

The cleaning tubes herein may be either or both of the type illustrated in this figure. Cleaning tubes 228 include the discharge ports or nozzles 229 and are closed by the caps 252. Cleaning tubes 228 include the discharge ports or nozzles 229 and are of the mechanical return bend type being united as at 256 and closed as at 251 so that they do not communicate one with the other insofar as each half of the tube is concerned relative to the other half.

-This, of, course, is desirable because cleaning fluid is injected into the cleaning tube under pressure for pressure discharge. That is why also return bend type cleaning tube, shown in Fig. 9, is closed or out off at the mid-portion.

Herein return bend type of cleaning tube, when used, is preferably so arranged that its curved portion is concentric with the curved portion 225 of the heat exchanger tubes. As stated, either or both forms of cleaning tubes may be incorporated with the heat exchanger or transfer tubes 22 6-221 shown in Fig. 11.

' While the invention has been illustrated and described in great detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims.

' The invention claimed is:

1. A cleaning device for insertion in a perforate cleaning tube disposed within a heat exchanger, comprising a fluid pressure supply tube of smaller diameter than said cleaning tube adapted for insertion longitudinally in the latter, a pair of spaced packing rings surrounding said fluid supply tube and adapted to engage the inner walls of said cleaning tube, an apertured sleeve surrounding said pressure supply tube hearing at its ends against adjacent faces of said packing rings, a stop holding one of said packing rings against sliding movement in one direction on said pressure supply tube, means supported by said pressure supply tube for exerting pressure against the other of said packing'rings in the direction of the said first ring, and said fluid pressure supply tube having perforations therein disposed between said packing rings.

2. A cleaning device for insertion in a perforate cleaning tube disposed within a heat exchanger, comprising a fluid pressure supply tube of smaller diameter than said cleaning tube adapted for insertion longitudinally in the latter, a head on the inner end of said pressure supply tube, a packing ring surrounding said supply tube and engaged with said head, an apertured sleeve surrounding said pressure supply tube and bearing at one end against said packing ring, a second packing ring surrounding said pressure supply tube and engaged with the opposite end of said sleeve, a tubular member threadedly engaged with the exterior of said pressure supply tube and bearing against said last named packing ring, and said pressure supply tube having openings therein communicating with the interior of said sleeve.

ROBERT W. DRAKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,152,423 Linaker Sept. 7, 1915 1,189,752 Thompson July 4, 1916 1,337,828 Dornbrook Apr. 20, 1920 1,598,238 Brooks Aug. 31, 1926 1,764,189 Bell June 17, 1930 1,928,090 Bowers Sept. 26, 1933 2,121,493 Thomas et a1 June 21, 1938 2,132,093 Bennett Oct. 4, 1938 2,302,513 Abraham, Jr. Nov. 17, 1942 2,538,701 Meyer Jan. 16, 1951 FOREIGN PATENTS Number Country Date 515,811 Great Britain Dec. 14, 1939 

